Florida · Balsa sticks, 1/16 to 1/4 in
14.2 in gap · a testing machine pressing on the roadway at mid-span · 110 g max
Official rules (PDF)(opens in a new tab)The rules don't mention AI tools. Check with your teacher or the organizer before you enter a design from this site. The judges suggest checking your design with free bridge software before you build it.
“A team shall consist of three students who shall construct the bridge.”Read it in the rulebook(opens in a new tab)
Soon this page will show ready-made designs for this contest, each checked against every rule below, loaded until it breaks, and buildable with a hobby knife, with a printable build pack. For now, here are the rules in plain words.
Our summary of the official rules. If anything here disagrees with the rulebook or the organizer, they win.
Where a rule can be read two ways we use the reading the organizer most likely meant and show the other. Where ours is the looser one, ask your organizer before you rely on it.
Figure 5 foundation: seats 7 cm long, 2 in above the trough floor, 36 cm apart, 4 in wide, with end walls (1 in tall, assumed).
The other reading: Other wall heights.
The 4 cm block slides along the trough floor and fills its full width, so the bridge may hang at most 0.425 in below the seats.
The other reading: A narrower block.
Superstructure height is the bridge's overall height.
“block which is 35.0 cm in length and 4.0 cm in height to pass underneath”
“maximum allowable superstructure height is 20 cm ... minimum ... 10 cm”
“approximately level surface ... car can roll across with a light push”
“width of the roadway ... not less than 5 cm ... not exceed 10 cm”
“length of the roadway ... not less than 40 cm ... not exceed 50 cm”
“members with a width and height not to exceed 0.635 cm”
“Maximum built-up are 3/4 in”
“total weight of the superstructure shall not exceed 110.0 grams”
“allow for the testing of the roadway at the middle of the structure”
“load resisted drops to zero or ... contact the base of the foundation”
The other reading: Height above the roadway.
Roadway length is the bridge's overall length; roadway width is its out-to-out width at deck level; a toy car's wheels run on stringers at +-0.5 in.
The other reading: A full-width deck surface.
The platen is about 1 in across; a roadway at the bottom needs a 1.25 in clear shaft above mid-span.
The other reading: A larger platen.